The 1926 United States Senate election in Oklahoma took place on November 2, 1926. Incumbent Republican Senator John W. Harreld ran for re-election to a second term. After facing many challengers in a crowded Republican primary, he advanced to the general election. In the Democratic primary, Congressman Elmer Thomas beat out a similarly crowded field, which included former Governor Jack C. Walton, to win his party's nomination with a plurality. In the general election, Thomas defeated Harreld in a landslide, winning his first of four terms in the U.S. Senate.